This invention relates to an improved boring bar sleeve for mounting different diameter and length boring bars within a single boring bar sleeve secured within the tool holder of a machine tool.
Machine tools which utilize boring bars for performing boring cutting of work pieces, commonly include a tool holder positioned upon a turret or other machine part. The tool holders include a socket within which a boring bar sleeve is fastened. The boring bar, an elongated shaft having a cutter or cutting insert fastened on its lead end, is inserted within the sleeve for mounting it upon the tool holder.
The diameters and lengths of boring bars vary considerably depending upon the particular machining operation required. Therefore, it is common to utilize different boring bar mounting sleeves, that is, mounting sleeves which have different diameter interior openings, for receiving correspondingly different diameter boring bars.
Since fastening a boring bar sleeve in the tool holding socket of a machine tool requires some time and labor, it is desirable to avoid moving or replacing the sleeve in order to accommodate each different size boring bar. Moreover, since a variety of different size boring bars requires an equally large variety of sleeves, it would be desirable to provide some means for reducing the number of sleeves so as to reduce the expenses and the storage of numerous sleeves.
Further, since boring bars are available in different lengths and, since the distance that a boring bar extends forwardly of the open end of the sleeve may vary, it is difficult to provide a single sleeve for properly holding boring bars relative to the tool holder. Thus, it would be desirable to have a universal sleeve means which permits the use of different diameter and length boring bars and different diameter extension lengths without changing the boring bar sleeve or moving it relative to the tool holder socket.
Thus, this invention relates to a boring bar sleeve having a major portion which is universally useable with different diameters, lengths and extensions of boring bars mounted upon tool holders of machine tools.